1. Technical Field
The present disclosure relates to a single focal length lens system, an interchangeable lens apparatus, and a camera system.
2. Description of Related Art
In recent years, interchangeable-lens type digital camera systems (also referred to simply as “camera systems”, hereinafter) have been spreading rapidly. Such interchangeable-lens type digital camera systems make it possible to photograph a high-quality image with high sensitivity, to enable high-speed focusing and high-speed image processing after the photographing, and to enable easy replacement of an interchangeable lens apparatus in accordance with a desired scene.
Conventionally, there has been a demand for a lens system which is compact and has high optical performance as a lens system used in an interchangeable lens apparatus. For example, various lens systems having a three-unit configuration have been proposed.
Unexamined Japanese Patent Publication Nos. 2012-242472 and 2013-037080 disclose a lens system having positive-negative-positive three-unit configuration. In this lens system, an aperture diaphragm is disposed in the first lens unit, and focusing is performed using the second lens unit.